All kinds of pests flock to our gardens: aphids, spider mites, caterpillars, mealybugs, you name it. They’re all beneficial and serve a role in the ecosystem, whether by pollinating or as food for predators, but if there’s an abundance and they’re taking a toll on your plants, that’s when things get annoying.
Turns out, certain plants are more of a magnet for pests than others. I spoke to three experts to find out what they are and what can done to make our gardens less of a buffet going forward. Here’s what they had to say…
1. Roses
While roses are known to be as hardy as they are beautiful, they will make pests congregate from far and wide, according to Lucie Bradley, expert gardener with Easy Garden Irrigation:
‘Roses can be highly attractive to a range of unwanted garden pests, notably aphids, as well as red spider mites, leafhoppers and rose sawflies. As these hungry insects pierce plant tissue to suck out the sugary sap, they not only cause physical damage to the roses, usually stunting growth and distorting flower development, but they also leave behind “honeydew”, a sticky fluid that makes your plants more susceptible to black sooty mould, which reduces effective photosynthesis. To protect your roses, you need to use a balanced rose food, rather than one high in nitrogen, which leads to weaker, soft growth that’s easy for them to feed on.’
If you’re looking to replace roses with something less alluring, Angelika Zaber, lawn care specialist and gardening expert working for Online Turf, says:
‘As an alternative, try growing peonies instead. These are known to be hardy, low-maintenance perennials that are less prone to pests than roses. This is especially true if you already have ants in your garden. The ants provide them with natural pest control, taking some of their sweet nectar in exchange for keeping sap-sucking insects away.
‘If you prefer to keep your roses, companion planting is a great way to keep the pests away. Lavender, marigolds or sage are all great choices as their strong scent will mask the smell of roses, confusing pests. You can also attract beneficial predators, such as ladybirds and hoverflies, that naturally feed on pests like aphids, reducing their population in your garden.’
2. Hostas
Hostas are another sturdy perennial, known for their vibrant leaves and shade tolerance, but these too are a pest magnet.
‘Hostas are well known to be attractive to slugs and snails, with these slimy pests happily eating the big leaves and leaving big holes as a result,’ continues Lucie. ‘They do this as their vibrant, fleshy leaves are rich in moisture and soft enough that they are easy to chew through compared with many other plants in your garden.
‘To deter slugs and snails, you can select varieties with thicker leaves, which are more resistant to the pests, such as “Sum and Substance”, which have robust, thick leaves, or “Big Daddy”, with its heavily puckered, large leaves that are harder for these pests to chew through. You can also discourage slugs and snails by using wool pellets or sharp grit close to your plants, as well as attracting their natural predators into your garden to control their numbers, including wild birds, frogs and toads.’
Used coffee grounds are another handy method for protecting your hostas – just dig them into the soil around the plant and they will help to deter slugs and snails. Keep in mind coffee grounds are toxic to cats and dogs, though, so skip this tip if you have pets. If the plant is potted, you could also try copper tape. Avoid killing slugs and snails where possible; they help break down matter in your garden and they’re food for many predators.
3. Tomato plants
‘While delicious, tomatoes are known to attract many pests, including aphids, leafminers, mealybugs, caterpillars, plant bugs, thrips and more,’ says Angelika. ‘This is because the plant has a strong, pleasant smell and high nutritional value, making it an ideal food source.
‘As an alternative, look into ground cherries. These tend to handle pests better as they grow with a paper-like shield around them, preventing many insects from getting to the fruit. When growing, make sure to do so in a greenhouse or a polytunnel for a good harvest.
‘Tomatoes, just like roses, can benefit from strong-smelling companion plants, such as marigolds, to keep them hidden from pests. You can also improve air circulation by spacing the plants three to four feet apart and keeping the bottom six inches of the plant free of leaves to reduce soil-borne pests. You can also harvest tomatoes as soon as they start turning red. At this stage, most of the flavour development is done and there is less chance of larger pests, like birds, damaging them.’
If you’re growing tomatoes outside and bad weather is imminent, you can harvest green tomatoes and use them for pickling or chutney. Or you can put them in bowl alongside a ripe banana on a windowsill and they will redden on their own.
4. Pansies
Built for British weather, pansies are often found clustered together in flowerbeds and windowboxes. They’re bright, colourful and keep their flowers when many others fade away. However, they’re as attractive to pests as they are to us.
‘Pansies attract troublesome pests like aphids and whiteflies together with slug and snails,’ explains Lucie. ‘They thrive when grown in moisture-rich soil and cool conditions, and these perfectly match the preferred environment for slugs and snails. At the same time, it’s the soft, tender foliage of pansies that makes them attractive to sap-sucking aphids and whiteflies.
‘To protect your pansies from slugs and snails, try to make the area less comfortable for these crawling visitors, which involves careful spacing when planting to ensure good airflow and less watering in the mornings, so the soil has dried before these nocturnal pests are at their most active. You can also use sharp grip, eggshells or wool pellets to make it hard for crawling pests to reach your plants. In terms of sap-sucking pests, you can organically control their numbers by attracting beneficial insects into your garden, such as ladybirds and lacewings, as well as using neem oil or insecticidal soaps to clear pests from your plants.’
5. Dahlias
The final plant to make our list is the dahlia, known for its ease of growth and range of vibrant flowerheads.
‘They are also known to be magnets for a wide range of garden pests that are attracted by their young, fast-growing, tender shoots, which are rich in sugary plant sap and high in water content,’ says Lucie. ‘This is why you will find them attracting aphids, leafhoppers, spider mites and thrips as well as slugs and snails, which can easily devour young plants overnight when new shoots first emerge.
‘In the first instance, you can protect the young, tender growth from being eaten by slugs and snails by starting dahlias off in pots and transferring them into their final growing places when they’re larger and sturdier. You could also use slug deterrents (as mentioned earlier) to create a barrier around your dahlias that these crawling pests won’t want to cross. To help protect dahlias from sap-sucking pests, you should keep them strong and healthy by removing lower leaves for good airflow, removing damaged foliage where insects would be happy to shelter and by watering deeply at ground level, keeping their foliage from being damp and humid, which insects favour. You can also encourage beneficial insects like ladybirds, lacewings and hoverflies into your garden, while using natural treatments such as neem oil or insecticidal soap.’
It’s worth pointing out that it’s better to grow a more diverse range of plants than to remove those that attract pests altogether. Every pest serves a purpose in the ecosystem, so you should avoid going out of your way to hurt them where possible.
Elizabeth Waddington, garden designer and writer at First Tunnels, says: ‘It is important to remember that healthy, organic gardens don’t seek to eradicate garden pests altogether. Rather, they should aim for a natural balance, where pests are kept in check by the creatures that eat or prey on them. To achieve that balance, we should not aim to get rid of pest species altogether, because if we do, we lose the creatures that keep their numbers down and potentially create conditions for a bigger pest problem to arise in future.
‘It’s worth thinking about the garden as a whole, rather than focusing on individual plants. A monoculture or large planting of one particularly susceptible crop can provide pests with an abundant and easily accessible food source. By contrast, a diverse planting scheme, with a mixture of flowers, herbs, shrubs and vegetables, can make it harder for some pests to locate their preferred host plants and can provide habitat and food for predators.’
